25/2-2

General

Well 25/2-2 is located east of the Frigg Field and south of the Frigg Øst Field, on the top of an E-W trending structure. The well was drilled to appraise the 25/2-1 Øst Frigg Discovery made in September 1973. The main target was lower Eocene sands where seismic sections displayed a bright spot in the western part of the closure just below the Frigg sand horizon. Secondary targets were Danian and Maastrichtian sands.

Operations and results

Appraisal well 25/2-2 was spudded with the semi-submersible installation Deepsea Driller on 31 May 1974 and drilled to TD at 2740 m in the Late Cretaceous Shetland Group.

Top Early Eocene sands (Frigg Formation) were encountered at 1949 m, 23 m lower than prognosed. The Hermod Formation came in at 2269 m while Danian sand (Ty Formation) was encountered at 2563 m and chalky limestone (Shetland Group) at 2703 m. Hermod and Ty were water wet. An increase in C1 and C2 at around 1950 m during drilling marked the top of the Frigg Formation reservoir. From electrical logs, FIT's and the DST Gas/oil and oil/water contacts were set at 1964.2 m and 1974.4 m, respectively. Three cores were cut from 1991 to 2012.5 m. The cores consisted almost entirely of sand with only some thin interbeds of silt in core number 2. Down to 2011 m the cored sands were brown coloured from oil stain, and direct fluorescence and cuts were very strong. No shows were observed from 2011 m to 2015.5 m in the base 1.5 m of core number 3. The DST carried out in the cored interval produced only water. Weak shows were recorded in the Ty Formation sands. Two FIT's at 1952 and 1968.2 in the Frigg Formation reservoir sampled gas and oil and recorded formation temperatures of 57.6 °C and 57.9 °C, respectively.

The well was permanently abandoned on 11 July 1974 as an oil and gas appraisal.

Testing

DST 1 carried out from 1983 to 1996 m produced 5.1 m3 of salt water (53 g/1).